A key change, effectively requiring lone parents to seek work or training as soon as their youngest child reaches seven years of age, takes effect next Wednesday.

Sinn Féin yesterday castigated Labour as Mary Lou McDonald accused the Tánaiste of misleading people about what were effectively welfare cuts costing some families up to €87 per week.

"The aspirational talk about returning to work will not compensate these families and these women for a cut of that magnitude, that's the bottom line," Ms McDonald told the Dáil. She said it was "no wonder" many Labour TDs were concerned about the issue.

Ms Burton later met four TDs - John Lyons, Joanna Tuffy, Robert Dowds and Michael Conaghan - along with Senator Marie Moloney, to hear their concerns.

It is understood that she said she would look at detailed ways of helping ensure the changes did not give rise to hardship and undue income loss due to the impact of the changes on other benefits.

Labour TD Joe Costello, who has also expressed concerns, said the party remained committed to the changes. "The reality is that lone parents have been stuck in a poverty trap and this is an effort to allow them another more worthwhile way," he said.

A spokesman for Ms Burton last night made it clear that the planned changes would go ahead. "But the Tánaiste is concerned that all possibilities to help ensure there is no undue loss of income will be looked at," the spokesman said.

He added that two-thirds of the lone parents, or some 20,000 families, would have no loss of income or may even gain as a result of changes to the system. The remaining 10,000 families will have the chance to take up more work opportunities.

Lone parent groups say the reforms will end up penalising many single parents working part-time and could force many to give up work.